The present invention relates to an electronic component, in particular a component operating with surface acoustic waves. More specifically, the invention relates to a component system formed of electrically conductive structures disposed on a substrate. The structures are mounted so as to make electrical contact with a base plate and are covered by a protective coating for protecting the structures from environmental influences.
It is known for electronic components to be protected by protective coatings against environmental influences, for example, to be protected against attacks by chemical substances such as moisture. For example, U.S. Pat. No. 3,438,873 describes the protection of semiconductor components by protective coatings of silicon nitride, aluminum oxide and mixed silicates such as aluminum silicate. In this case, the protective coating is applied directly onto the system of the semiconductor component. The term component system in this case describes the substrate which contains the active electronic parts of the component. In other words, the component system is thus the component excluding any housing containing it.
In certain electronic components, it may not be sensible, and may even be damaging to the component function, to apply a protective coating of the above type onto the component system itself. This is the case, for example, with components operating with surface acoustic waves, since a protective coating applied onto the component system of such components can adversely affect the propagation of surface acoustic waves. Another example of this would be sensors for mechanical stresses, since mechanical forces caused by the protective coating in the sensor system may influence the detection of mechanical stresses to be measured.
It is accordingly an object of the invention to provide an electronic component, in particular a component operating with surface acoustic waves which overcomes the above-mentioned disadvantages of the prior art devices of this general type, which protects electronic components against environmental influences without the adverse effects which can occur from protective coatings applied onto the component systems.
With the foregoing and other objects in view there is provided, in accordance with the invention, an electronic component, including: a base plate; a component system having a substrate and electrically conductive structures disposed on the substrate, the component system electrically contacting the base plate in a connecting region; and a protective coating shielding the component system, the protective coating forming an environmental proof seal protecting the component system against environmental influences toward the base plate, the protective coating is one of a metal coating and a partial coating of metal.
In accordance with an added feature of the invention, the component system is mounted on the base plate using flip-chip technology.
In accordance with another feature of the invention, the component system is mounted on the base plate and electrically contacts the base plate with wire contacts.
In accordance with an additional feature of the invention, the substrate has a side facing away from the connecting region, the protective coating is applied toward the base plate to the side of the substrate facing away from the connecting region between the component system and the base plate forming the environmental proof seal toward the base plate.
In accordance with a further added feature of the invention, there is a plastic covering disposed between the component system and the protective coating, and the protective coating is applied to the plastic covering toward the base plate for forming the environmental proof seal toward the base plate.
In accordance with a further additional feature of the invention, the protective coating is a coating formed from a plurality of partial coatings.
In accordance with another added feature of the invention, at least one of the plurality of partial coatings is a glass coating.
In accordance with another additional feature of the invention, the glass coating is a lower partial coating of a partial coating sequence.
In accordance with yet another feature of the invention, there is a corrosion protective coating disposed on the protective coating.
In accordance with an added feature of the invention, there is an adhesive coating disposed under the protective coating.
In accordance with an additional feature of the invention, the metal coating forming the protective coating is also an electrical contact.
In accordance with another feature of the invention, the metal coating and the partial coating of metal forming the protective coating is applied by one of vapor deposition, vacuum metallization, electrochemical treatment, and lamination.
In accordance with a concomitant feature of the invention, the component system is a surface acoustic wave component system.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an electronic component, in particular a component operating with surface acoustic waves, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.